Impure Mouse is an Easter Egg, and an antagonist in the game Five Nights at Treasure Island. It is currently unknown what her effect on gameplay will be.
Impure Mouse appears to be a Minnie Mouse suit, with no eyes and a pair of huge human-like teeth.
Impure Mouse will begin in Character Prep 1, offscreen. Then, she will appear in the room, hanging. This can help the player prepare for her to move.
If Impure Mouse appears in the office, the player needs to pull up the monitor and shut off a camera, to lure her to another room. Delaying or neglecting to do so will cause her to kill the player. The player also has the option to hide under the desk, giving the player a 50/50 chance of surviving. Impure Mouse will always disappear, reappearing in Character Prep 1 later.
Impure Mouse will start off-camera, then she will start hanging in Character Prep 1, move to the Staff Area, move to the Meat Freezer, move to the Lounge, and eventually enter The Office.
Impure Mouse saying "This isn't how we're supposed to be"
Impure Mouse saying "Why do I exist?"
Impure Mouse laughing.